The invention relates to a pipe clamp for securing together, for example, two pipes or one pipe and an end cover. The pipe clamp comprises two clamping members that are hinged at one end and comprise a securing device at the other end.
There exists a multitude of pipe clamps for securing together two pipe ends. For example, DE 2911575 describes a type of pipe clamp comprising an outer clamping member consisting of two parts that are hinged together at one end and comprise a securing device at the other end. Two abutting elements are arranged inside the clamping member. The abutting elements are moved relative to the clamping member when it is closed. It is also disclosed that there may be another securing device instead of a hinge. DE 3038491 also describes a clamp device for securing together two pipe ends which, for example, may be in two halves that are either hinged together or have two securing devices.
Pipe clamps for large pipes are available on the market, the pipe clamp in this case having to withstand substantial forces and consisting of three parts which are hinged together at two points and comprise a securing device at the third point. These clamps are made in three parts in order to overcome a number of disadvantages encountered in two-part clamps.
Pipe clamps in two parts, where the parts are configured as pure circular arcs that are hinged at one end and have a securing device at the other, require that the clamp be opened wide to enable a pipe with end hub to be inserted into the pipe clamp. This may mean that the securing device must also be placed further out from a centre point of the pipe clamp. The insertion of a pipe end and the opening of the clamp are a problem area, and therefore many clamps with two parts are made with securing devices at both ends. This means that there are two devices that must be secured together, and for a clamp that is fitted, for example, under water, this is a cost-increasing factor. It is also a cost-increasing factor in the production of the clamp. Alternatively, the number of parts in the clamp can be increased. When a pipe clamp consisting of two parts configured as pure circular arcs is to be closed, the end points of the circular arcs will meet the pipe hub first. This results in a point contact, and with large clamps that must withstand substantial forces, the point will tend to dig into the contact face and this may result in the clamp not being able to form the desired connection.
When using clamps under water, it is also a problem that the clamp cannot be fully open, that is to say that the pipe ends must be inserted into the clamp from the side of the clamp, whilst it is a great advantage if there is only one element that must be actuated to open and close the clamp. This means to say that the clamp must consist of parts which are drawn apart on opening, whilst there is an element that holds them together for the closing and opening of the clamp. For the clamp to be opened wide, the securing device must be placed further away from a centre point of the clamp so as not to obstruct the insertion of the pipe ends. This results in a less advantageous clamp with an unfavourable distribution of forces.
In particular for use under water, it is desirable that the clamp should be capable of being closed in a simple manner and with great force, partly so that the clamp may straighten out possible angular differences between the two hubs that are to be secured together. (With hub it is meant the hub part of a hubbed flange.)
One of the objects of the present invention is to provide a pipe clamp consisting of two pipe clamp parts which are hinged at one end and comprise a securing device at the other end, and which overcomes the aforementioned disadvantages of known pipe clamps.
It is an object to provide a pipe clamp that does not need to be opened as wide as previously known pipe clamps, whilst the securing device is in a favourable position. It is a further object to avoid point contact between the clamp and the pipe hub during closing of the clamp.
It is also an object to provide a pipe clamp which can be closed with such great force that any angle between the pipe hub ends is straightened by the clamp.
The aforementioned objects are obtained by a pipe clamp as disclosed in the claims below.